Axel Vogt

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20 Badges

20 years, 259 days
Munich, Bavaria, Germany

MaplePrimes Activity


These are replies submitted by Axel Vogt

Can we have some details beyond advertising slang?

Personally I am 'only' interested in the Math improvements and would like to hear about them.
Currently mathematics for engineering applications, performance improvements and DE are
named ...

You are welcome, but - as far as my limited English allows me to guess the 'hidden' insult - you also are supposed to use the communication style of adults, even if you joined the forum just 1/2 an hour ago.

You are welcome, but - as far as my limited English allows me to guess the 'hidden' insult - you also are supposed to use the communication style of adults, even if you joined the forum just 1/2 an hour ago.

It understands the semantics without using a formal language.

It understands the semantics without using a formal language.

When I looked at your blog here in the morning CET, then I saw just 2 entries and in the afternoon (my last post) it was visible again.

So I guess it is the board software, which may be buggy.

But it is hard to believe Maple intentionally deleted something.

I also just looked through the 'non-published' entries (which is the usual very state before something is deleted): there is none from you and the subcase of such blog entries are only 9 (!), so it is easy to check (the first is a test post by a user from 2005, the last is a job offer from 2008)

For example:

www.mapleprimes.com/blog/alec/numerical-inverse-laplace-transform-0

So may be the links where broken, it works now for me: www.mapleprimes.com/blog/alec
(where I had to quit loading because of the video, that's terrible with slow connections).

???

f:= x -> x^2 +1- exp(-1/(110*(x-1))^2) is bad, because it has a singularity
in x=1. Which can be lifted, but discont(f(x), x) will show it without lift.

With lifting I would split according to a piecewise situation.

Even then one has to care for "bad" boundary situations: on 1.4 ... 1.0 it
does not work as 'expected', while on 0.0 ... 1.0 it works.

Comparing f(1) and f(1.0) shows a different behaviour: the first results in
'division by 0' while the second (used by hardware floats in maximize) does
not. And I think it tells, that Maple does not try to analyze the situation
automatically, but quickly hands it over to a solver coded for floats. And
it is just good luck, that f(1.0) works due to rounding errors.

Also I have the impression, that the maximizer starts in the left boundary
and does *not* escape from there in your situation (i.e. a good example) .


By the way: I always would work with Digits = 14 for first shots.
f:= x -> x^2 +1- exp(-1/(110*(x-1))^2) is bad, because it has a singularity
in x=1. Which can be lifted, but discont(f(x), x) will show it without lift.

With lifting I would split according to a piecewise situation.

Even then one has to care for "bad" boundary situations: on 1.4 ... 1.0 it
does not work as 'expected', while on 0.0 ... 1.0 it works.

Comparing f(1) and f(1.0) shows a different behaviour: the first results in
'division by 0' while the second (used by hardware floats in maximize) does
not. And I think it tells, that Maple does not try to analyze the situation
automatically, but quickly hands it over to a solver coded for floats. And
it is just good luck, that f(1.0) works due to rounding errors.

Also I have the impression, that the maximizer starts in the left boundary
and does *not* escape from there in your situation (i.e. a good example) .


By the way: I always would work with Digits = 14 for first shots.

Hm ... de.wikipedia.org/wiki/Griechisches_Alphabet (where I miss the possibilty to switch to the English version en.wikipedia.org/wiki/Greek_alphabet (which is not just a translation, it is different)

Concurrently in German it is officially written as jota - but that is just a transcription. The german Wiki article actually suggests to write it as iota. Which buffeled me. Searching a bit more gave me the impression, that it comes in through different translation of old Bible texts via a Gotic version by Wulfila ~ 350 A.D. where it should have been written as iota. Since it is unique within the text ( = Matthäus 5,18) it should be possible to find it. Though it is an interesting way of time killing I gave up ...

Back to the topic: Maple is not actually a type setting tool, so what ... there is still Latex to torture oneself :-)

Hm ... de.wikipedia.org/wiki/Griechisches_Alphabet (where I miss the possibilty to switch to the English version en.wikipedia.org/wiki/Greek_alphabet (which is not just a translation, it is different)

Concurrently in German it is officially written as jota - but that is just a transcription. The german Wiki article actually suggests to write it as iota. Which buffeled me. Searching a bit more gave me the impression, that it comes in through different translation of old Bible texts via a Gotic version by Wulfila ~ 350 A.D. where it should have been written as iota. Since it is unique within the text ( = Matthäus 5,18) it should be possible to find it. Though it is an interesting way of time killing I gave up ...

Back to the topic: Maple is not actually a type setting tool, so what ... there is still Latex to torture oneself :-)

Not sure whether you mean country settings (mine is German for Win XP), but it prints just 'jota'.

Not sure whether you mean country settings (mine is German for Win XP), but it prints just 'jota'.

And how sad, that the docu is not more clear on Powmod and powmod in its statements (i.e. telling also in Math terms, not only by Maple commands).

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